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Appearance. Concrete has a more rocky texture, feel, appearance to it than pure cement does, Rudin says. Cement is more versatile: It can be made to feel glassy smooth or just as rocky as concrete.
The resulting hard substance, called 'clinker', is then ground with a small amount of gypsum (CaSO 4 ·2H 2 O) into a powder to make ordinary Portland cement, the most commonly used type of cement (often referred to as OPC). Portland cement is a basic ingredient of concrete, mortar, and most non-specialty grout. The most common use for Portland ...
A w/c ratio higher than 0.60 is not acceptable as fresh concrete becomes "soup" [2] and leads to a higher porosity and to very poor quality hardened concrete as publicly stated by Prof. Gustave Magnel (1889-1955, Ghent University, Belgium) during an official address to American building contractors at the occasion of one of his visits in the ...
Pavers manufactured from concrete go well with flag, brick and concrete walkways or patios. Concrete pavers may be used where winter temperatures dip below freezing. They are available in hole, x-shape, y-shape, pentagon, polygon and fan styles. An interlocking concrete paver, also known as a segmental paver, is a type of paver.
Other manufacturers were thus compelled to use other terminology to describe the process such as shotcrete, pneumatic concrete, guncrete, etc. Shotcrete is an all-inclusive term for spraying concrete or mortar with either a dry or wet mix process. However, shotcrete may also sometimes be used to distinguish wet-mix from the dry-mix method.
Concrete has a very low coefficient of thermal expansion, and as it matures concrete shrinks. All concrete structures will crack to some extent, due to shrinkage and tension. Concrete which is subjected to long-duration forces is prone to creep. The density of concrete varies, but is around 2,400 kilograms per cubic metre (150 lb/cu ft). [1]
Unlike regular concrete, ECC has a tensile strain capacity in the range of 3–7%, [1] compared to 0.01% for ordinary portland cement (OPC) paste, mortar or concrete. ECC therefore acts more like a ductile metal material rather than a brittle glass material (as does OPC concrete), leading to a wide variety of applications.
High-strength concrete has a compressive strength greater than 40 MPa (6000 psi). In the UK, BS EN 206-1 [3] defines High strength concrete as concrete with a compressive strength class higher than C50/60. High-strength concrete is made by lowering the water-cement (W/C) ratio to 0.35 or lower.